Chand, is that a company wide policy? May I ask what company you work for? Steve At 10:52 PM 9/13/2006, chand basha wrote: >charles, >your are right both are equally importent. >but we cant give equal priority to both and its not possible also. >to ensure the smooth functioning of the board we put more priority to core. >pcb engg cant do anything to affect the core power but he also cant assure the >stability of the power ! ! ! >now dont you feel core powe should be stable inorder to work the >system properly ? > >Thanks >chand > > > > >"Grasso, Charles" <Charles.Grasso@xxxxxxxxxxxx> wrote: >I guess I'm confused. Aren't they ALL "important"? The core power and=20 >the I/O power will have defined ripple specifications and so the PDS has >to be designed to accommodate both. > > >Best Regards >Charles Grasso >Compliance Engineer >Echostar Communications Corp. >Tel: 303-706-5467 >Fax: 303-799-6222 >Cell: 303-204-2974 >Pager/Short Message: 3032042974@xxxxxxxxx >Email: charles.grasso@xxxxxxxxxxxx > > >-----Original Message----- >From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] >On Behalf Of Ken Cantrell >Sent: Wednesday, September 13, 2006 8:22 AM >To: Brad Crowell; Ken.Cantrell@xxxxxxxxxxxxxxxx; weirsi@xxxxxxxxxx; >chand_374@xxxxxxxxx; zhuyongfa@xxxxxxxxxx; si-list@xxxxxxxxxxxxx >Cc: jinzhaoguo@xxxxxxxxxx; 'zhang kun@huawei' >Subject: [SI-LIST] Re: which type of power(core logic power or I/O >power) has a high priority > >Brad - >The answer is the same on a single part basis. >Ken > >Message----- >From: Brad Crowell [mailto:bcrowell@xxxxxxxxxxx] >Sent: Wednesday, September 13, 2006 8:04 AM >To: Ken.Cantrell@xxxxxxxxxxxxxxxx; weirsi@xxxxxxxxxx; >chand_374@xxxxxxxxx; zhuyongfa@xxxxxxxxxx; si-list@xxxxxxxxxxxxx >Cc: jinzhaoguo@xxxxxxxxxx; 'zhang kun@huawei' >Subject: RE: [SI-LIST] Re: which type of power(core logic power or I/O >power) has a high priority > > >Ken, >But is that for IO or core power that is the most important? Which >device is >the biggest concern is a different question than which power rail to a >given >device is the biggest concern. >Brad > >-----Original Message----- >From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] >On >Behalf Of Ken Cantrell >Sent: Wednesday, September 13, 2006 10:46 AM >To: weirsi@xxxxxxxxxx; bcrowell@xxxxxxxxxxx; chand_374@xxxxxxxxx; >zhuyongfa@xxxxxxxxxx; si-list@xxxxxxxxxxxxx >Cc: jinzhaoguo@xxxxxxxxxx; 'zhang kun@huawei' >Subject: [SI-LIST] Re: which type of power(core logic power or I/O >power) >has a high priority > >Brad - >Read the data sheet for the parts involved. See how much current and at >what dI/dt each chip uses. The one(s) with the most/fastest current >consumption are the ones that take priority. >Ken > >-----Original Message----- >From: si-list-bounce@xxxxxxxxxxxxx >[mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of steve weir >Sent: Wednesday, September 13, 2006 6:06 AM >To: bcrowell@xxxxxxxxxxx; chand_374@xxxxxxxxx; zhuyongfa@xxxxxxxxxx; >si-list@xxxxxxxxxxxxx >Cc: jinzhaoguo@xxxxxxxxxx; 'zhang kun@huawei' >Subject: [SI-LIST] Re: which type of power(core logic power or I/O >power) has a high priority > > >Brad, I think you didn't see other responses because there is no correct >rule of thumb answer. At the end of the day, one needs to analyze the >requirements for all supplies. Often I/O needs priority. But, that is >not >something to depend on. > >Steve. >At 04:47 AM 9/13/2006, Brad Crowell wrote: > >I didn't see any other responses go by and was wondering if their were > >any other opinions on this matter. From a PCB perspective, I would > >suggest that the IO power would be more important. Not to suggest that > >core power isn't also important, but there is less the PCB designer can > >do to affect the quality of core power on an IC. To some degree, if the > >chip designer hasn't taken care of the power supply design of the > >IC/package, then the PCB >cannot > >fix it. Alternatively, the outputs are what induce currents on the PCB > >and what the PCB designer should be more concerned with. I would be > >interested in hearing other opinions. > > > >Thanks > >Brad > > > >-----Original Message----- > >From: si-list-bounce@xxxxxxxxxxxxx > >[mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of chand basha > >Sent: Wednesday, September 06, 2006 6:45 AM > >To: zhuyongfa@xxxxxxxxxx; si-list@xxxxxxxxxxxxx > >Cc: jinzhaoguo@xxxxxxxxxx; zhang kun@huawei > >Subject: [SI-LIST] Re: which type of power(core logic power or I/O > >power) has a high priority > > > >zhuyongfa > > its core logic power which will get the highest priority.(for > >stabilised operation of the device) > > > > Thanks > > chand > > > > > >z46147 wrote: > > Hi everyone, > >In pcb design, there are several type of power(core logic power, I/O >power). > >In some designs we can not provide GND planes for each power type, when >that > >happens, which power type(core logic power, I/O power) we should give > >priority to close with GND plane? As we all know, core logic power > >always gives rise to EMI problem, and > > > >Thanks and regards! > > > >Zhuyongfa > >Huawei Technologies Co., Ltd. > >Bantian, Longgang District > >Shenzhen 518129, P.R.China > >Tel:+86-755-89650717 > >mail:zhuyongfa@xxxxxxxxxx > > > > > >------------------------------------------------------------------ > >To unsubscribe from si-list: > >si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > > >or to administer your membership from a web page, go to: > >//www.freelists.org/webpage/si-list > > > >For help: > >si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > >List FAQ wiki page is located at: > >http://si-list.org/wiki/wiki.pl?Si-List_FAQ > > > >List technical documents are available at: > >http://www.si-list.org > > > >List archives are viewable at: > >//www.freelists.org/archives/si-list > >or at our remote archives: > >http://groups.yahoo.com/group/si-list/messages > >Old (prior to June 6, 2001) list archives are viewable at: > >http://www.qsl.net/wb6tpu > > > > > > > > > > > >--------------------------------- > >Get your own web address for just $1.99/1st yr. 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